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Large variability of the K uroshio at 23.75°N east of T aiwan
Author(s) -
Jan Sen,
Yang Yiing Jang,
Wang Joe,
Mensah Vigan,
Kuo TienHsia,
Chiou MingDa,
Chern ChingSheng,
Chang MingHuei,
Chien Hwa
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2014jc010614
Subject(s) - geostrophic wind , hydrography , current (fluid) , oceanography , environmental science , climatology , geology
Synoptic features of the Kuroshio at 23.75°N were quantified using nine ship‐based surveys between September 2012 and September 2014. The new ship‐based data set provides an unprecedented view of the Kuroshio east of Taiwan and suggest tremendous variability in its velocity, hydrography, volume, heat, and salt transports, and water masses. The Kuroshio maximum velocity varied in 0.7–1.4 m s −1 ; the core current width, delineated with the limit v ≥ 0.2 m s −1 , ranged from 85 to 135 km, and the thickness varied from 400 to 600 m. A dual velocity maximum in the Kuroshio core current, though unexpected, was observed in three of nine cruises. The Kuroshio core transport, integrated from the directly measured velocity, varied between 10.46 and 22.92 Sv (1 Sv=10 6 m 3 s −1 ). The corresponding heat transport referenced to 0°C was 0.838–1.793 × 10 15 W, and the salt transport was 345.0–775.9 × 10 6 kg s −1 . The geostrophic transport estimated using the thermal wind relation with the observed hydrographic data and reference velocity at 900 m is comparable to the directly measured Kuroshio transport during most of the surveys, suggesting the directly measured velocity is mostly in geostrophic balance.